Whenever we eat or drink, a chain reaction of intense proportions begins. Teeth and muscles are mashing, pulpy juices are flowing, chemicals are firing and valves are opening and closing with the synchronicity of rocket science.

The digestive system mechanically, chemically and bacterially converts substances to energy, nutrients and waste. It is regulated by hormones and the autonomic nervous system.

Parts Involved for Digestion

Mouth (salivary glands, mucosa, teeth, tongue)

Pharynx – the throat, where the digestive and respiratory tracts intersect

Although you cannot certainly control your ANS, many lifestyle choices you make determine how it functions. The more you realize the physiological consequences of how you live, the easier it becomes to make choices with awareness, develop habits that serve your greater good and live easier. It takes patience, diligence and a sense of humor to get the new rhythms going, but once flowing you’ll certainly reap more than you sowed.

Remember, you’re not designed to be stressed all the time, even moderately. Not really digesting, pumping blood under higher pressure than needed, with tired eyes and poorly nourished skin, it’s a surefire way to compromise your fine-tuning and experience dis-ease, ultimately creating disease. There is nothing decadent about nourishing yourself with rest, gentleness, inspiration and whatever makes you thankful to be alive, especially if you do it in ways that support the same in others.

Long-Term Tension

If your muscles are contracted in a semi-permanent state of being, blood and impulses are not flowing optimally. At some point, the flow has been compromised for so long that our minds decide this must be the new regular state-of-being. Your body is then officially engaged in maintaining a physical habit (see below). Furthermore, continued troubles do not just affect the specific location, but radiate to other systems like the fascia and skin (puckers, dimples, cellulite), pressuring confined organs and creating numbness and/or discomfort which can illicit a myriad of symptoms.

Injuries

Just like with tension, blood and information flow are compromised if you injured yourself (twisted ankle, broken leg) or had surgery (scar tissue, muscle atrophy). Too often we also have a fear of re-injuring or over-stressing these parts, and sometimes our brains send out a “Do Not Use” order even after the area has healed. This indicates that we are acting on old information and avoiding the chance of re-experiencing pain and injury. Fear or no fear, messages to and from headquarters can get pretty muddled, and like a bureaucracy, after awhile one hand doesn’t know exactly what the other one’s doing! Let’s remember that it’s always possible to reeducate and rejuvenate the body and mind to flow optimally.

Physical Habits

Most of us are aware of some habits, and unaware of others. Things we hear people say:

Working closely with the nervous and circulatory systems, the endocrine system is a regulatory system of ductless glands secreting chemical messengers (hormones) to coordinate many cellular activities. Each of the 30+ hormones conducts unique business in the body such as managing body temperature, sleep cycles, weight, puberty, other age-related changes, and how you handle stress.

Some chemicals are created by the organ that uses them, while others are emitted into the bloodstream to serve distant functions. Most of the time we are unaware of all this business, although sometimes when we temporarily feel ‘funny’, it very well could be that our endocrine system initiated a new activity while we were sensitive enough to detect the change.

Made up of your brain, your spinal chord, and a 47 mile network of nerves that thread through your body, the nervous system is the communication center for coordinating actions and reactions. Using chemistry, electricity and bundles of sensory cells (neurons), messages are rapidly delivered to and from your central nervous system.

When a nerve is stimulated, an electrical impulse is created, and travels down the finger of the neuron. At the end of the neuron, the impulse triggers chemicals to assist the impulse in jumping to the next neuron. This process repeats until the message is delivered, and occurs far faster than it took you to read this. Neurons can be very tiny, three feet long, and everything in between.

The somatic nervous system processes voluntary motor actions and the autonomic nervous system controls the actions that we do not willfully control. The autonomic nervous system is divided into the sympathetic and the parasympathetic subsystems, which work in tandem like our government’s branches of checks and balances (sometimes there’s a team and sometimes it’s gridlock). To learn more about the autonomic subsystems, peruse Neurology.

Parts Involved in the Nervous System

Brain & spinal chord – central nervous system

Nerve pathways throughout the body make the peripheral nervous system

Neurons – thin threads of nerve cells bundled together to form ‘telephone wires’ of communication

Nervous Functions

Collects vast quantities of information about body state in relation to environmental state, analyzes and adjusts to satisfy needs, most powerfully, survival

The reproductive system perpetuates our species by fusing two cells from different genders introduced through sexual intercourse or artificial insemination. Both genders create, ripen, store and transfer their respective sex cells (called gametes). Gametes in both sexes are created in a process called meiosis.

When gametes combine successfully, the merged sperm and ovum form a zygote; 7-10 days later, the still dividing and growing formation implants in the uterus and becomes an embryo. About eight weeks later, the embryo has developed into a fetus, which continues to develop into an infant, born after nine months of gestation.

Cowper’s gland – produces a tiny amount of fluid in the outer penis that neutralizes any traces of acidic urine and lubricates the penis and female tract just prior to ejaculation (correlated to the female’s Bartholin glands)

Female Parts Involved

Ovarian follicles (monthly fibro-vascular coatings produced around oocyctes) – produced around all oocytes that go through meiosis in monthly cycle, one of which secretes estrogen which triggers the thickening of the uterine lining and ripens the egg (ovulation)

Fallopian tubes (fimbriae) – the fimbriae coax the ripened egg down the tube, where it is fertilized or not

Fun Facts

According to the Guinness Book of World’s Records, in the 18th century, a Russian peasant gave birth to 69 children over 40 years. Amongst them were 16 pairs of twins, 7 sets of triplets and 4 sets of quadruplets.

If an egg is not fertilized within 12-24 hours of being released from the follicle, it dissolves.

The clitoris is the only organ in humans seemingly designed purely for pleasure. It has twice the nerve endings of the entire penis.

Infant girls are born with 30,000 oocytes present in their ovaries! After reaching puberty, males typically produce 12 billion sperm per month!

The cardiovascular system delivers oxygen and nutrients to the whole body, defends against infections, transports hormones, and collects waste products that end up in the excretory system.

Parts Involved

Heart – the extremely consistent pumping organ

Blood (plasma, red blood cells, white blood cells, platelets)

Vascular system (arteries, veins, capillaries)

Bone marrow – produces blood cells

Liver – produces plasma

Functions

Pulmonary circulation pumps to lungs for the release of carbon dioxide and the intake of oxygen.

Systemic circulation pumps oxygen-rich blood to the body. Splanchnic or visceral circulation supplies the digestive organs as a branch directly off the aorta. Before it returns to the heart, blood supplied to the gastrointestinal tract goes to the liver (known as portal circulation) where nutrients are absorbed and toxins are neutralized. There is also a small portal flow from the hypothalamus to the anterior pituitary gland.

Fetal circulation obtains oxygen and nutrients from the placenta through the umbilical chord rather than the lungs and the mouth.

Fun Facts

If the vascular system of one person were laid end to end, it would circle the globe twice!

The heart pumps about 3,600 gallons (13,640 liters) of blood per day.

The heartbeat is the sound of the valves closing as they push blood through its chambers.